The Kittila mine is situated within the Kittila Greenstone belt, part of the Lapland Greenstone belt in the Proterozoic-age Svecofennian geologic province. The appearance and geology of the area is similar to that of the Abitibi region of the Canadian Shield. In northern Finland, the bedrock is typically covered by a thin but uniform blanket of unconsolidated glacial till. Bedrock exposures are scarce and irregularly distributed.

The mine area is underlain by mafic volcanic and sedimentary rocks metamorphosed to greenschist assemblages and assigned to the Kittila group. The major rock units trend north to north-northeast and are near-vertical. The volcanics are further sub-divided into iron-rich tholeiitic basalts located to the west and magnesium-rich tholeiitic basalt, coarse volcaniclastic units, graphitic schist and minor chemical sedimentary rocks located to the east. The contact between these two rock units consists of a transitional zone (the "Porkonen Formation") varying between 50 and 200 metres in thickness. This zone is strongly sheared, brecciated and characterized by intense hydrothermal alteration and gold mineralization, features consistent with major brittle-ductile deformation zones. The zone is part of a major north-northeast-oriented shear zone (the "Suurikuusikko Trend").

The Porkonen Formation hosts the Kittila gold deposit, which contains multiple mineralized zones stretching over a strike length of more than 25 kilometres. Most of the work at the Kittila mine has been focused on the 4.5-kilometre stretch that hosts the known gold in mineral reserves and mineral resources. From north to south, the zones are Rimminvuoma ("Rimpi-S"), the deep extension of Rimminvuoma ("Rimpi Deep"), North Rouravaara ("Roura-N"), Central Rouravaara ("Roura-C"), depth extension of Rouravaara and Suurikuusikko ("Suuri/Roura Deep"), Suurikuusikko ("Suuri"), Etela and Ketola. The Suuri and Suuri/Roura Deep zones include several parallel sub-zones that have previously been referred to as Main East, Main Central and Main West. The Suuri zone hosts approximately 15% of the current probable gold reserve estimate on a contained-gold basis, while Suuri Deep has approximately 21%, Roura-C approximately 4%, Roura Deep approximately 27%, Rimpi Deep approximately 28% and Rimpi-S approximately 5%.

Gold mineralization in these zones is associated with intense hydrothermal alteration (carbonate- albite-sulphide), and is almost exclusively refractory, locked inside fine-grained sulphide minerals: arsenopyrite (approximately 73%) or pyrite (approximately 23%). The rest is free gold, which is manifested as extremely small grains of gold in pyrite.

The orebodies at Kittila were initially mined from two open pits, followed by underground operations to mine the deposits further beneath the surface.

Underground mining commenced in the fourth quarter of 2010 and, at the end of 2016, a total of 6.5 million tonnes of ore has been mined from the underground portion of the mine.

At the Kittila mine, the Suurikuusikko and the Rouravaara orebodies are currently mined by underground mining methods and access to the underground mine is via ramp. Approximately 5,000 tonnes of ore per day are fed to the concentrator, exceeding the nominal capacity of 3,750 tonnes per day. The underground mining method is open stoping with delayed backfill. Stopes are between 25 and 40 metres high and yield between 8,000 and 40,000 tonnes of ore per stope. To ensure sufficient ore production is available in the future to supply the mill, over 15,000 metres of tunnels will be developed each year. After extraction, stopes are filled with paste backfill or cemented backfill to enable the safe extraction of ore in adjacent stopes. Ore is trucked to the surface crusher via the ramp access system.

Construction of the processing plant and associated equipment was completed in 2008. Facilities at the Kittila mine include office buildings, a maintenance facility for mining equipment, a warehouse, a second maintenance shop, an oxygen plant, a processing plant, a paste backfill plant, a tank farm, a crusher, conveyor housings, an ore bin and a sulfate removal plant at the NP3 tailings area. In addition, there are some temporary structures for contractor offices and work areas.

The ore at the Kittila mine is treated by grinding, flotation, pressure oxidation and CIL circuits. After grinding, ore processing consists of two stages. In the first stage, ore is enriched by flotation and, in the second stage, the gold is extracted by pressure oxidation and CIL processes. At the end of the second stage, gold is recovered from the carbon in a Zadra elution circuit and recovered from the solution using electrowinning and finally poured into dore bars using an electric induction furnace.